Carboxylic acids sucrose oxidation products

The catalytic oxidation of sucrose is described in several patents. This oxidation ought to lead to a uronic acid derivative from which D-glu-curonic acid could be obtained by hydrolysis. This acid has, indeed, been obtained in this manner but, according to our experience," the catalytic oxidation of sucrose does not proceed uniformly. All three susceptible primary hydroxyl groups, on C-1 and C-6 of the D-fructose residue and at C-6 of the D-glucose residue, are oxidized at a similar rate and, therefore, a reaction product is obtained which contains all of the expected mono- and di-carboxylic acids, and which presents a difficult problem in separation. 

Synthesis from sucrose ester/half-ester derivatives, monoepoxide and diisocyanate. Sucrose "penta"-soyate (the methanol insoluble fraction of the soap-free product) was reacted at 100°C for 4 hours with a mixture in xylene of 1 mole equivalent cyclic anhydride e.g., phthalic or tetrahydrophthalic anhydride and monoepoxide e.g., styrene oxide or Cardura E (the glycidyl ester of versatic acid), branched C9-Cfatty acids, in the presence of N-benzyl dimethylamine as catalyst. A faster rate was achieved with the phthalic system. The course of reaction between half ester carboxyl groups and epoxide groups was followed by acid value. About 90% reaction was achieved in all cases and to the product was added 1.0 mole toluene diisocyanate (the meucimum amount without gelation) and dibutyl tin dilaurate as catalyst. 

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